Figs. 6 and 7 show the current/voltage characteristics for the positive and negative plasmas, respectively. The slopes of these curves are the total circuit impedance which is the sum of the internal resistance of the power supply at low power, it is about 20 , the plasma impedance, and the resistance of the water. It can be seen that the total impedance decreases as the plasmas are driven at higher power. This is almost certainly due to a decrease in plasma impedance as more charge carriers are generated. A minimum resistance is also seen in each current/voltage characteristic. For the negative plasma Fig. 6, the minimum impedance is about 300 . For the positive plasma Fig. 6, the minimum is approximately, 1,070 . In the future, the plasma electrodes will be scaled up and powered using a remote source e.g., microwave excitation that is independent of the bias voltage on the electrodes. Using this method, both the plasma resistance and the electrode voltages can be substantially reduced. For example, using Eq. 10 and an electron temperature equivalent to 1 eV, the collision frequency at atmospheric pressure is found to be = 2.21012 s?1. Further assuming a plasma density n= 1014 cm?3, the expression for the resistivity is used to compute may be evaluated as = 77 cm. If the plasma coupling regions are columnar approximate diameter of 50 mm and height of 25 mm their resistance, R, can be calculated using Eq. 11 R = H A 11 where = bulk resistivity cm, H= height cm in the coupling regions, and A= plasma flux area cm2 . The operation of Eq. 11 with these data yields R= 10 . When the metal electrode was substituted for one or the other of the plasma electrodes furious bubbling, in fact frothing, at the immersed metal electrode was observed. This was true even though the plasmas were generated from a small area on the water e.g., only a few millimeters in diameter. If plasma of only a few square millimeters area could cause such fast bubbling, it is certainly natural to speculate about spreading the plasmas out into sheets, or about having arrays of small plasmas for large-scale hydrogen production. The metal immersion electrode also gave a strong indication that much of the electrolysis occurred near the surface as shown in Fig. 7. If current was nominally flowing through the water bulk, there should be a linear or at least relatively smooth relationship between the immersion depth of the electrode and the current, provided that the applied voltage is constant. In fact, Figs. 7 both positive and negative plasma shows a linear region highlighted by the dashed line, but it is displaced upward in current. Both figures also show a pronounced break in the curve at a depth of about 4 mm. From this observation, it is thought that only a small amount of current flows through the water bulk. In the case of the positive plasma in Fig. 7, at a depth of about 2 cm it would appear that 33 mA is flowing in the first 4 mm of the water and the remainder of 44 mA that is 11 mA is flowing in the rest of the bulk. Thus, about 75% flows are on the surface. Similarly, from negative plasma shown in Fig. 7, it can be estimated that about 88% of the current between the negative plasma and the immersed electrode flows on the surface. The quantitative difference between the two plasmas in the current may be due to a difference in current carriers. The thickness of the surface layer estimated at approximately 4 mm is only very rough since the effects of the meniscus formed by the water at the immersion electrode have not been taken into account. In future work, similar experiments will be repeated with a fully immersed counter electrode and a water layer of controlled depth.
6. ADVANTAGES OF HYDROGEN FUEL: Hydrogen fuel is more effective than all other fuels . It has following advantages on ordinary fuel:
• Hydrogen can store energy rather than other fuels ,in the form of liquids and gas which will not dissipate until we used in any application.
• Hydrogen fuel is more efficient ,its efficiency is about 25%,in power plant it is 35% as a whole the efficiency is more than 80%.
• Hydrogen fuel is environmental friendly .In the combustion of these fuels no pollutants are produced .
• Hydrogen fuel can be used world wide for domestic uses. Specially US community uses mostly domestically.
• High reliability
• Reduced the demand of oil.
• Greenhouse gas emission reduced.
• Renewable energy sources.
BY replacing hydrocarbon economy by hydrogen economy makes a dramatic change world wide.
6. disadvantage of hydrogen fuel:
• Nitrogen Dioxide gas emission cause harmful effects
• Production of hydrogen fuel is very much cosly.
• Highly flammable
• Storage issue
• Climate change aggrevati